How to listen to method invokation using Dart reflection?

i read a bit about dart mirrors but I did not figure out how to listen to method invocation using dart reflection.

Use Case:

Buttons in Flutter can have an onTap() method which is invoked when an user taps on that button.

I would like to listen to that invokation of onTap() using dart reflection to fire my own code when that happens...

how to realize that?